Morphological and Molecular Profiling of Cercophora sp. and Studying Its Potential Effect on Legume Growth Performance Under Drought Conditions

Cercophora species, typically known as saprobes or coprophiles, have occasionally been isolated from healthy roots and have recently been recognized as endophytes. Their dark-pigmented structures suggest adaptation traits similar to dark septate endophytes, although their symbiotic potential remains unclear. This study isolated and characterized Cercophora sp. NPKC241 from mung bean roots grown under artificial drought in soils with different fertilization histories, using PCR-based DNA sequencing and morphological observation. Its effects on legume growth were subsequently evaluated through pot inoculation experiments under drought. These experiments focused on mung bean, a species known to exhibit significant reductions in chlorophyll content and yield under drought conditions. Among 29 isolates, Cercophora sp. consistently promoted legume growth. In mung bean, it increased shoot and root mass, chlorophyll content, and root elongation under both optimal and water-limited conditions. Under drought, inoculated plants showed approximately threefold higher chlorophyll levels, two- to threefold greater biomass, and roots approximately 5 cm longer than the control, indicating mitigation of drought-induced physiological decline. These findings suggest that Cercophora sp. can act as a beneficial root-associated fungus, enhancing legume performance under drought. Future studies will further explore this interaction by underlying physiological mechanisms and the field-level application potential.